Spatial discrimination in patients with MSA, PSP, DIP, and VP with pain.

Pain is common in Parkinson's disease and frequently observed in other diseases involving parkinsonism. Abnormal scaling function in PD has been reportedly associated with pain, but the role of this function in pain in other parkinsonism-related diseases remains unknown. We screened 127 patients with multiple system atrophy (MSA, n = 24), progressive supranuclear palsy (PSP, n = 15), drug-induced parkinsonism (DIP, n = 56), or vascular parkinsonism (VP, n = 32). After screening, 79 patients with parkinsonism (23 MSA, 10 PSP, 28 DIP, and 18 VP patients) were included in the study. We divided the patients of each group into two groups (with or without pain).The percentages of patients in those groups with pain were 73.9%, 50.0%, 67.9%, and 66.7%, respectively. There was no difference in mean SDT between patients with and without pain in any disease (all p ≥ 0.052). The number of patients showing unmeasurable SDT did not differ between those with and without pain in any disease (all p ≥ 0.316). Our study found no evidence of a role of scaling function in pain development in parkinsonian disorders such as atypical parkinsonism, DIP, and VP.